gistfile1.txt

#!/usr/bin/env bash
# runscript.sh
# Usage: ./runscript.sh <ip-address>

set -euo pipefail

IP_ADDRESS=${1:-}
if [[ -z $IP_ADDRESS ]]; then
  echo "Usage: $0 <ip-address>"
  exit 1
fi

# 1) lookup ENI
eni=$(aws ec2 describe-network-interfaces \
  --filters "Name=private-ip-address,Values=$IP_ADDRESS" \
  --query 'NetworkInterfaces[0]' \
  --output json 2>/dev/null) || eni="null"

if [[ -z $eni || $eni == "null" ]]; then
  echo "IP $IP_ADDRESS → not found"
  exit 0
fi

# extract helpers
interface_type=$(jq -r '.InterfaceType // ""' <<<"$eni")
description  =$(jq -r '.Description   // ""' <<<"$eni")
attach_id    =$(jq -r '.Attachment.InstanceId // ""' <<<"$eni")

# 2) classify

## 2.1 Lambda
if [[ $interface_type == "lambda" ]]; then
  # drop prefix
  lambda_full=${description#AWS Lambda VPC ENI-}
  # remove trailing UUID (8-4-4-4-12 hex) + anything after (e.g. colon)
  lambda_name=$(printf '%s' "$lambda_full" |
    sed -E 's/-[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}.*$//')
  echo "Lambda $lambda_name"
  exit 0
fi

## 2.2 NLB
if [[ $interface_type == "network_load_balancer" ]]; then
  # "ELB net/<NLB-name>/…"
  nlb_full=${description#ELB net/}
  nlb_name=${nlb_full%%/*}
  echo "NLB $nlb_name"
  exit 0
fi

## 2.3 ALB
if [[ $description == ELB\ app/* ]]; then
  # "ELB app/<ALB-name>/…"
  alb_full=${description#ELB app/}
  alb_name=${alb_full%%/*}
  echo "ALB $alb_name"
  exit 0
fi

## 2.4 Classic ELB
if [[ $interface_type == "interface" && $description == ELB\ * ]]; then
  # "ELB <ELB-name>"
  elb_name=${description#ELB }
  echo "ELB $elb_name"
  exit 0
fi

## 2.5 ECS
ecs_arn=$(jq -r '.TagSet[]? | select(.Key=="aws:ecs:taskArn") | .Value' <<<"$eni")
if [[ -n $ecs_arn ]]; then
  echo "ECS $ecs_arn"
  exit 0
fi

## 2.6 EKS branch
if [[ $interface_type == "branch" ]]; then
  echo "EKS branch"
  exit 0
fi

## 2.7 EKS trunk
eks_node=$(jq -r '.TagSet[]? | select(.Key=="node.k8s.amazonaws.com/instance_id") | .Value' <<<"$eni")
if [[ -n $eks_node ]]; then
  node_name=$(aws ec2 describe-instances \
    --instance-ids "$eks_node" \
    --query 'Reservations[0].Instances[0].Tags[?Key==`Name`].Value|[0]' \
    --output text 2>/dev/null || echo "")
  echo "EKS ${node_name:-$eks_node}"
  exit 0
fi

## 2.8 EC2
if [[ -n $attach_id ]]; then
  inst_name=$(aws ec2 describe-instances \
    --instance-ids "$attach_id" \
    --query 'Reservations[0].Instances[0].Tags[?Key==`Name`].Value|[0]' \
    --output text 2>/dev/null || echo "")
  echo "EC2 ${inst_name:-$attach_id}"
  exit 0
fi

# 2.9 fallback
echo "Other"
exit 0